The cracking of masonry structures is a very well known phenomenon. Concrete walls, concrete block walls, stone walls and brick walls are all very susceptible to cracking. This cracking is sometimes due to distortion caused by movements in the foundation of the masonry structure. In other cases, crack formation is caused by vibrations in the masonry structure and/or drying out subsequent to the construction of the structure. Such cracking can occur after various time periods including shortly after the masonry structure is constructed to periods many years after the construction of the structure. Unfortunately, such cracks are generally transmitted through layers of paint which coat such masonry structures.
Masonry structures are painted with exterior coatings of varying thicknesses both to provide the masonry structure with a degree of protection and as a decoration. The propagation of cracks through the coating destroys both the coatings aesthetic beauty and the protection that it provides to the masonry structure. Cracks which are transmitted through such an exterior coating layer are both unsightly and provide a point at which moisture can penetrate into the masonry structure. For example, wind can drive rain into such cracks with the moisture being further transmitted into the structure by capillary forces into the interior of the structure causing dampness, degradation of the material, and a reduction of the thermal insulation efficiency of the masonry structure. At the same time, an acceleration in the degradation of the exterior takes place due to moisture and its expansion during freezing which acts between the coating and substrate as well as opening the crack in the masonry structure even wider.
Systems are known which are designed to fill or cover cracks which have already formed, such as sealants and mastics. These materials have a chewing gum-like consistency which will accommodate a certain degree of crack enlargement, but at the same time have limited adhesion. Flexible coating systems are partially effective, but do not offer a totally satisfactory solution for cracking in masonry structures.